Safety Regulations for NHRA Classes and Brackets

A Mustang GT and a Fiesta Rally car at an unknown track. The Tree has just gone green and both drivers are launching.Image credit: http://motrolix.com

If you plan to enter your vehicle in any competition sanctioned by the NHRA, your strip burner is going to have to pass a series of pre-race inspections for the required safety equipment. This is true even for the classes which contain “street legal” vehicles, i.e. your “daily drivers.” These requirements get more stringent as the expected horsepower and speeds increase.

We’ve talked before about the different brackets and classes in NHRA racing, but here we’re going to break down the rules and regulations of each of the classes in terms of safety, focusing on the ones that don’t require huge financial backing and professional status Since one of my colleagues has already done a fine job of listing most of the mechanical requirements for the Eliminator classes here and here, I’m going to focus on the safety regulations and requirements of each. Everything that I’m going to cover here is covered in more detail in the NHRA General Regulations. I am in no way going to be able to cover everything in the space I have here, so I recommend you bookmark that link, or, if possible, print the PDF document.

What You Need to Know for E.T. Handicap Racing

The NHRA allows every track to make its own E.T. and class titles, so each division may have different provisions for or against certain devices like launch delays and throttle stops. These allowances may also vary from region to region. If you’re curious about the legality of certain devices in your area/track, you should contact the pertinent division office for more info.

Other vehicle-control devices such as counters and time displays are forbidden unless otherwise specified in the Class Requirements. Devices that are strictly forbidden include those that display or transmit track location, or provide time and/or distance data. Data recorders, except playback tachometers are allowed in Advanced E.T. and Super Pro classes, while they are prohibited in all other classes. Those tuning computers you see in movies like “The Fast and the Furious” are also strictly verboten.

Some Safety Requirements Are the Same for All Classes

The NHRA states that any vehicle other than a motorcycle that is capable of doing 135 MPH or better has to conform to the minimum safety requirements for a car that can do the quarter on 9.99 seconds. This means there are certain driver credentialing requirements as well as safety clothing requirements for all competitors. If you’re planning on entering an E.T. Bracket motorcycle, no matter its top speed, you’re going to have to comply with the restrictions for a 9.99 second vehicle.

You may not need a racing harness, but I do recommend them.Image credit: http://www.apvsafetyproducts.com

Basic NHRA Safety Requirements

The basic safety stuff for the street legal classes is pretty simple. You’ve got to have working seatbelts. Your headlights and taillights also have to be fully functioning, and not just for show. The car’s battery must be properly secured. I usually use a battery box.

Like I said, this stuff is pretty much a no-brainer, but your car also must have street legal tires. This means they must have a safe amount of tread and be DOT-approved. All cars must be equipped with mufflers. If you’re running nitrous, your bottle must meet minimum 1,800 pound requirements and have the DOT stamp to prove it. Check with your local track for more info here as most of those additional requirements are at their discretion.

What’s Under Your Hood?

Engine requirements are pretty simple. If you’re entering a car, you’ve got to have a single automobile engine. Motorcycles can only have a single motorcycle engine. And so on. Your car’s engine must be equipped with a harmonic dampener/balancer that meets or exceeds SFI 18.1 requirements if the car is capable of running in the high 10s or better. NHRA allows competition exhaust systems, but they have to vent out the back, away from both the driver and fuel tank. These engine regulations are covered in NHRA General Regulations 1:1 while exhaust regulations are covered in Section 1:3. Keep in mind, especially if you have an older vehicle, that the engine cooling system must be closed with an overflow receptacle that can hold at least 16 ounces. See Regulation 1:7 for more.

Fuel System Safety Requirements

Back in the 80’s when I was racing, there was hardly a weekend event where someone’s car didn’t catch fire when they drifted and hit the guardrail. For this reason, NHRA Safety Regulations state that any fuel filler neck that is located inside the vehicle’s trunk must vent to the outside of the vehicle. Vented caps are also prohibited as they allow gas fumes out, which can cause a fire. Personally, I prefer fuel cells over stock tanks.

Many racers these days put special batteries, fuel lines, pumps, and more in the trunk. If you plan on doing this as a way of balancing the front-rear weight distribution better, you’re going to have to install a complete bulkhead isolating the driver compartment from the trunk. This bulkhead must be made of at least .024 inch thick steel or .032 inch aluminum. Under no circumstances may a fuel line run through the driver compartment. See General Regulations 1:5 for more information.

Fuel Induction Systems

According to Regulation 9:1, you can have whatever type of fuel induction system you want. Blown, turbocharged, dual turbos, superchargers, or any combination thereof, are all legal (Regulation 1.10). If you have a fuel injection system, it must be a closed-loop OEM-type system. EFI systems may only monitor basic engine functions. The monitoring of any performance parameters such as wheel speed, driveshaft speed, and acceleration is also strictly verboten. If your car has an OEM EFi system that is an open-loop system that is factory, it’s permitted. These lower level classes and brackets prohibit the use of nitromethane, but they do allow pretty much anything else, however, water-methanol injection systems, completely mounted/installed outside the driver compartment, are legal. Provisos for this type of system include, as mentioned that none of the system’s piping, tubing, etc. may be installed in the driver compartment and it must be installed and used to manufacturer specifications.
So what if I want to install an aftermarket injection system on my older car? Not a problem whatsoever as long as you find it on the list of approved EFI systems.

Transmission, Driveline, and Rear-End Regulations

Clutches and flywheels on cars running 11.49 or better must meet SFI Spec 1.1 (Single-disc) or 1.2 (two disc max) requirements. These requirements, as well as those for flywheel shields and bellhousings are covered in Regulations 2:3, 2:5, 2:6, and 2:10. General Regulation 2:4 covers drivelines. The highlight of this is that if your car is capable of turning 13.99 or better with slicks (111.49 or slower with street tires) the driveline must have a loop to keep it in place. If your car came from the factory as an all-wheel-drive vehicle, you’re OK, but you can’t retrofit with one.

This is also true for all cars equipped with locker diffs. Speaking of differentials, if your car weighs more than 2,000 pounds, is equipped with an independent rear but without upper and lower control arms, you’re going to have to replace the rear-end with a standard housing assembly-one similar to what you find in a 63-82 Vette. If your car has both upper and lower controls, you can keep the swing-arm rear, period. However, General Regulation 2:11 states that both axles must be equipped with retention loops.

Brakes, Suspension, and Steering

These get pretty involved, but I will mention that no matter what kind of car or how fast it can go, it’s got to be equipped with hydraulic brakes. Brake regulations are covered in 3:1. Steering systems are covered in Regulations 3:3 and 4:1.

Cars that are stock-bodied (which are the ones we’re talking about here)must be equipped with a full automotive suspension system. There has to be at least one hydraulic shock on each sprung wheel. You may not lighten or otherwise compromise any stock suspension components. Rigid mounted suspensions are also strictly forbidden. Regulations 3:2, 3:4, and 3:5 cover these items, while 3:6 states you can have nonmetallic wheelie bars.

Frame Requirements

Regulation 4:2 states that you can ballast your frame, meaning you can add weight to it. General Regulation 4:5 covers ground clearance and states that you’ve got to have a minimum ground clearance of three inches in from the front of the car to 12 inches behind the front axle’s centerline. Except for the oil pan and headers, the rest of the car can have two inches of clearance. According to 4:8, if your car can top 150, you my friend must have a parachute.

Roll Cage/Roll Bar Requirements

Certain cars are going to require a roll cage.

From my experience, where most first-timers run into trouble is when it comes to roll bars and cages. Personally, every car I build gets a full five or six point roll cage with rhino bars covering the doors. However, not all cars require them. Regulations 4:10 and 10:6 cover this issue. If your car is capable of running between 11-flat and 11.49 seconds has to have a roll bar. Any convertible running between 11 and 134.49 seconds must also have at least a roll bar.

Roll cages are mandatory for any car either running 10.99 or quicker or capable of exceeding 135 MPH must be equipped with a roll cage. Cars that run between 7.5 and 9.99 must have their frames and cages recertified every three years by the NHRA. The result of this certification is a serial number sticker being affixed. There are many more requirements covering roll cages, roll bars, and their associated (and required) padding. These are found in 4:10, 4:11, and 10:6.

Let’s Take a Look at Your Interior

Yes, there are actually NHRA regulations that cover the interior of your car. All of these are classified as safety regulations. Regulation 6:2 covers seats and states that they must be properly braced and framed. Seats must also be supported and constructed of fiberglass, carbon fiber, double-layer poly, or aluminum. This regulation also states that the use of magnesium in the interior sheetmetal is forbidden as it burns easily and is next to impossible to put out. Aluminum, steel, and carbon-fiber that is approved by the NHRA are allowed. Any full-bodied car that rubs 135 or faster or can turn 7.5to 9.99 has to have an approved window net. The car must also be equipped with seatbelts. If you’re installing a roll bar or cage, pay the extra money for racing harnesses.

Individual Driver and Car Requirements

Every driver that enters an NHRA event must be in possession of a valid driver’s license. You must also possess the minimum level of liability insurance required by your state of residence. Some tracks may require more, such as a driver safety class. If your car is capable of going 9.99 or less, you’re going to need an NHRA competitor’s license. These aren’t terribly difficult to get.

There are also driver clothing requirements. Minimum clothing requirements include long pants, socks, and shoes with closed toes–no sandals. Clothing made of nylon is forbidden. You may also have to have a helmet and other safety equipment. These standards can also change from track to track. Also, if your car meets certain engine or speed requirements, you may be required to wear a safety/flame retardant suit, gloves, neck flash protection, racing shoes, etc.

What to Expect on Race Day

Dragsters staged prior to the start of the event.Image credit: http://www.dragracingonline.com

No matter what track you race at, there’s a set procedure that you will have to follow, with very little variation. This is what you can expect on race day:

Upon entry to the track, you’ll pay your entry fee and receive a tech card.

With your completed tech card in hand, head over to tech where they’ll perform a basic safety inspection of your car.

Once you pass tech, your next step is to head over to racer registration to sign a waiver and show your driver license.

Mike's love of cars began in the early 1970's when his father started taking him to his Chevron service station. He's done pretty much everything in the automotive aftermarket from gas station island attendant, parts counter, mechanic, and new and used sales. Mike also has experience in the amateur ranks of many of racing's sanctioning bodies.